During fiscal 1980-81, it is proposed to continue evaluation of Leucocyte Adherence Inhibition (LAI) analysis as a means for detection and diagnosis of cancer in man. Enough data should be available to begin preliminary evaluation using the matrix design originally described. In addition, comparisons with non-hemacytometer variants of the LAI system will be made. The availability of an Image Analyzer will permit experiments designed to quantify the test. The basic experiments will have been done by the end of the above fiscal year. Finally, experiments will be done to establish the role of HLA genetic restriction to tumor antigen presentation in elicitation of the LAI response. This will be done by means of analyses of HLA-typed families of tumor patients and by the use of specific anti-HLA sera. Preliminary experiments using as a model immunization of humans to keyhole limpet hemocyanin have revealed the likely existence of such a restraint.